1 | /** |
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2 | * Licensed to the Apache Software Foundation (ASF) under one |
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3 | * or more contributor license agreements. See the NOTICE file |
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4 | * distributed with this work for additional information |
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5 | * regarding copyright ownership. The ASF licenses this file |
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6 | * to you under the Apache License, Version 2.0 (the |
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7 | * "License"); you may not use this file except in compliance |
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8 | * with the License. You may obtain a copy of the License at |
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9 | * |
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10 | * http://www.apache.org/licenses/LICENSE-2.0 |
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11 | * |
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12 | * Unless required by applicable law or agreed to in writing, software |
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13 | * distributed under the License is distributed on an "AS IS" BASIS, |
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14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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15 | * See the License for the specific language governing permissions and |
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16 | * limitations under the License. |
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17 | */ |
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18 | package org.apache.hadoop.security; |
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19 | |
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20 | import java.io.IOException; |
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21 | import java.security.AccessController; |
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22 | import java.security.Principal; |
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23 | import java.util.Set; |
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24 | |
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25 | import javax.security.auth.Subject; |
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26 | import javax.security.auth.login.LoginException; |
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27 | |
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28 | import org.apache.commons.logging.Log; |
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29 | import org.apache.commons.logging.LogFactory; |
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30 | import org.apache.hadoop.conf.Configuration; |
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31 | import org.apache.hadoop.io.Writable; |
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32 | |
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33 | /** A {@link Writable} abstract class for storing user and groups information. |
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34 | */ |
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35 | public abstract class UserGroupInformation implements Writable, Principal { |
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36 | public static final Log LOG = LogFactory.getLog(UserGroupInformation.class); |
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37 | private static UserGroupInformation LOGIN_UGI = null; |
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38 | |
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39 | private static final ThreadLocal<Subject> currentUser = |
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40 | new ThreadLocal<Subject>(); |
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41 | |
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42 | /** @return the {@link UserGroupInformation} for the current thread */ |
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43 | public static UserGroupInformation getCurrentUGI() { |
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44 | Subject user = getCurrentUser(); |
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45 | |
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46 | if (user == null) { |
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47 | user = currentUser.get(); |
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48 | if (user == null) { |
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49 | return null; |
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50 | } |
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51 | } |
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52 | |
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53 | Set<UserGroupInformation> ugiPrincipals = |
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54 | user.getPrincipals(UserGroupInformation.class); |
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55 | |
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56 | UserGroupInformation ugi = null; |
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57 | if (ugiPrincipals != null && ugiPrincipals.size() == 1) { |
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58 | ugi = ugiPrincipals.iterator().next(); |
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59 | if (ugi == null) { |
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60 | throw new RuntimeException("Cannot find _current user_ UGI in the Subject!"); |
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61 | } |
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62 | } else { |
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63 | throw new RuntimeException("Cannot resolve current user from subject, " + |
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64 | "which had " + ugiPrincipals.size() + |
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65 | " UGI principals!"); |
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66 | } |
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67 | return ugi; |
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68 | } |
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69 | |
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70 | /** |
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71 | * Set the {@link UserGroupInformation} for the current thread |
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72 | * @deprecated Use {@link #setCurrentUser(UserGroupInformation)} |
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73 | */ |
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74 | @Deprecated |
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75 | public static void setCurrentUGI(UserGroupInformation ugi) { |
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76 | setCurrentUser(ugi); |
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77 | } |
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78 | |
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79 | /** |
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80 | * Return the current user <code>Subject</code>. |
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81 | * @return the current user <code>Subject</code> |
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82 | */ |
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83 | static Subject getCurrentUser() { |
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84 | return Subject.getSubject(AccessController.getContext()); |
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85 | } |
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86 | |
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87 | /** |
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88 | * Set the {@link UserGroupInformation} for the current thread |
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89 | * WARNING - This method should be used only in test cases and other exceptional |
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90 | * cases! |
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91 | * @param ugi {@link UserGroupInformation} for the current thread |
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92 | */ |
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93 | public static void setCurrentUser(UserGroupInformation ugi) { |
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94 | Subject user = SecurityUtil.getSubject(ugi); |
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95 | currentUser.set(user); |
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96 | } |
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97 | |
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98 | /** Get username |
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99 | * |
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100 | * @return the user's name |
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101 | */ |
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102 | public abstract String getUserName(); |
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103 | |
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104 | /** Get the name of the groups that the user belong to |
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105 | * |
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106 | * @return an array of group names |
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107 | */ |
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108 | public abstract String[] getGroupNames(); |
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109 | |
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110 | /** Login and return a UserGroupInformation object. */ |
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111 | public static UserGroupInformation login(Configuration conf |
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112 | ) throws LoginException { |
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113 | if (LOGIN_UGI == null) { |
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114 | LOGIN_UGI = UnixUserGroupInformation.login(conf); |
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115 | } |
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116 | return LOGIN_UGI; |
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117 | } |
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118 | |
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119 | /** Read a {@link UserGroupInformation} from conf */ |
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120 | public static UserGroupInformation readFrom(Configuration conf |
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121 | ) throws IOException { |
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122 | try { |
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123 | return UnixUserGroupInformation.readFromConf(conf, |
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124 | UnixUserGroupInformation.UGI_PROPERTY_NAME); |
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125 | } catch (LoginException e) { |
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126 | throw (IOException)new IOException().initCause(e); |
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127 | } |
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128 | } |
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129 | } |
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